Influence of steroid hormones on bovine pericardial calcification

Calcification is a frequent cause of the clinical failure of bioprosthetic heart valves fabricated from glutaraldehyde pretreated bovine pericardium (GABP). The present investigation describes the influence of steroid hormones in the mineralization of GABP, in an extra-circulatory environment. Calcification was studied on GABP incubation in a metastable solution of calcium phosphate containing steroid hormones such as estrone, progesterone, 7(OH) progesterone, testosterone and beta-estradiol. It is interesting to note that certain steroids can variably increase the GABP calcification. Further, the effect of these steroids in an in vitro hydroxyapatite (HA) formation was investigated. In addition, we observed these steroids alter the calcium transport through GABP in diffusion experiments and also in HA formation. Therefore, it is conceivable that prolonged use of steroids or steroids containing oral contraceptive agents may not be advisable for patients having bioprosthetic implants in contact with blood. A better understanding of the mechanism of these drugs under in vivo conditions is needed to develop applications.